The answer to that is a simple, "yes, no, maybe ..".
In general NPC use is for Quest runners, Ops and so on. However, if you ask very nicely, and are not to presumptive about it, then it is very possible that an Op will let you involve a few NPCs. You'll not get anything other than RP benefit from them and their powers/levesl will be limited, but they could make very good sword/spell fodder and, maybe, even a decent fireside tale of derring-do